Track-laying tractor



C. A. MURDOCK.

TRACK LAYING TRACTOR.

APPLICATION FILED Ams), 1919.

Patented Get. 28, 1919.

ED sTATEs PATE r CHARLES A. MURDOCK, OF STOCKTON, CALIFORNIA, ASSIGNOR- F ONE-HALF T0 FREDERICK L. LEVY, OF STOCKTON, CALIFORNIA.

TRACK-LAYING TRACTOR.

Specification of Letters Patent.

Patented Oct. 28, 1919.

To all whom t may concern:

Be 'it known that I, CHARLES A. MURDOGK, a citizen of the United States of America, residing at Stockton, in the county of San Joaquin and State of California, have invented certain new and useful Improvements lin Track-Laying Tractors; and I do l declare the following to be a clear, full, Aand p in track layin -larlythe track feature thereof, that there will be a minimum of track sections and joints and hence fewer parts to wear out.

Another feature of my invention is the elimination of the usual s rocket drive for the track, which ordinari y is in the form of a chain of some kind, necessitating a high grade of metal in the construction thereof.

My improved track sections are in the formV of slabs or great area and length rather than chains, and I am enabled to form of tractor havin form an endless drive therewith by the use of polygonal -wheels or tumblers in the manner more fully set forth hereinafter.

I have here-described and shown particularly on Figure 1 of the drawings, a the endless track feature only on' one si e thereof, the other side havingmerely a balance or supporting wheel. This type is particularly adapted to be used in the pulling of plows, where sharp turns are desirable, and which can be made in this case by turning the tractor about the supporting wheel as a pzifvot. However, it is'to be understood that I do not limit myself to having only one track, but ma use two if. so desired.

Anot er object of the invention is to produce a simple and inexpensive device and yet one which will= be exceedingly effective for the'purposes for which it is designed.

These ob]ects, I accomplish by means of vsuch structure and relative arrangement of the parts as will fully appear by a perusal of the following specification and claims.

- On the drawings, similar characters of reference 4indicate corresponding parts in the several views.

Fig. 1 is a side elevation of my improved tractor.

Fig. 2 is a cross section through the track unittaken on a line 2-2 of Fig. 1.

Fig. 3 is a fragmentary plan of a track section joint. Q

Fig. 4 is a longitudinal section of the same taken on a line 4 4 of Fig. 3.

Fig. 5 is a cross section of a modified manner of assembling a polygonal track-wheel or tumbler. V

Referring now more 4particularly to the lcharacters of reference on the drawings, the numeral 1 designates the outer longitudinal frames of the tractor-which are suitably spaced apart and have shafts 2 mounted under the same and transversely thereof at each end, and a predetermined distance apart. I

Keyed to the shafts 2 are equal sized wheels or 'tumblers 3 and 4 preferably of rectangular periphery, the rear one 4 of such `'wheels being connected to a chain sprocket drive 5 operated in the usual manner byja power plantA 6 mounted on the frame of the tractor to vone side of the outer Each of the tumblers Sand 4 comprises a pair of such rectangular members 3*l and 4*", respectively, `having hubs 7 projecting therebetween and adapted to abut when in position on the shafts 2 so that there is a considerable space, as at 8,4 between such rectangular portions.

Each corner of the members 3 and 4 has 9. wearing strip 9, of hard steel or similar long wearing material.' Adapted to pass around the tumblers 3 and 4 are track sections 10 linked together, each section havin a length from. center to center of links equa to the len h of one of the sides of the members 3 an 4.

' Each track section comprises a tread portion or shoe 11 extending across the members 3 and 4a or as wide as may be desired and still pass between the frames 1.` These shoes may `be constructed of wood of any thickness, and if so constructed may be sheathed in metal as at 12.

Central of each shoe and lengthwise thereof on the inner face of the same is a channel iron 13, or `similar structure, the width of such member being sufficient to permit it t0 pass in thespace 8 between the members 3a and 4.

These channels are of a height suiicient to conceal a hinge strap 14 secured to one end of each shoe inside the channel thereon, the in 15 of the hinge being rigidly secured to t e sides of the channel of the adjacent shoe and turning in the strap 14, there being a grease cup 16 secured to each strap and likewise concealed between the sides of the channel 13.

Pivotally mounted under the frames 1 on a shaft 17 on brackets 18 depending from the frames 1, is a truck-frame 19 carrying a pair of rollers 2O on each end thereof, the rollers riding on the inner faces of the shoes 11 at a level considerably below the level of the bottom of the members 3 and 4 and straddling the channels 13 thereof and forming guides for the track sections between the tumblers 3 and 4.

The pivotal shaft 17 is preferably central between the shafts 2 and also on a line with the shaft of a supporting wheel 21 mounted to the frame of the tractor on the farther side thereof from the endless track unit.

A tiller wheel 22 is mountedto the frame at the forward end thereof, the tiller wheel being operable from the drivers seat 23 by wheel 24 and suitable means of the steerin mechanism connected therewith.

Thus it will be seen that by the .use of this tiller wheel, and by any' suitable means to brake and hold the supportin wheel 21, the tractor maybe tur-ned on t at .side about the wheel 21 as apivot, thus making a very sha turn.

so it will be noted that the main weight of the tractorfis carried by the rollers 20 and the shoes therebeneath, relievin the tumblers 3 and 4' of this weight, anthus making it easier for them to turn without eat strain on their shafts and bearings an doing away with the necessity of making these' parts 'very heavy and cumbersome.

Also by reason of the fact'thatv the truck 19-720 holds the members 3 and 4 well above it, and has a rocking motion on the shaft 18 which is on la line, or may be one with, the shaft of the wheel 21, the tractor is enabled to tilt about this point, -when going over unevennesses in the ground surface, without the corners of the members 3 and 4 coming close enough to the ound to lift the tractor with the turning t ereof.

If it is desired to utilize a track having a pair of s aced hinges instead of the one here described, the members 3 and 4 may be reversed in position on the shafts, and bolted together to form a singlel wide `face, as shown in Fig. 5. l In this type the hinges of the tracks would be on the outside of the tumblers, instead of'between, and would of course necessitate certain changes 1n the detail of construction of the track sections, but `would not change the principle of operation thereof. v

From the foregoin description it will be readily seen that I ave roduced such a device as substantially fulgls the object of the invention asset forth herein.

vWhile this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as donot form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is 1. A tractor including a frame, polygonal sided tumblers turnably mounted at each end of the frame, one of the tumblers being operatively connected with the power plant of the tractor, an endless track passing around the tumblers, each link of the track having a length equal to that of each side of the tumblers, and means depending from the frame and pivoted thereto whereby the weightof `the tractor lis taken off the tumblers and the tractormay oscillate about such ivotal point. p

2. tractor including spaced longitudinal frames, rectangular tumblers turnably mounted between the frames, one of the tum- `blersbeing operatively connected 'with the power plant of the tractor, linked track sections passing over the tumblers and adapted to contact with the .ground at a lower level than the lowest lpoint of the tumblers, each track section having a length equalto that minne side of the tumblers, means `whereby such position .of the track sections is maintained and means on the track sections where blers.

3. Atractor including .spaced longitudinal frames, tumblers turnably mounted between the frames, each of the tumblers comy the same are guided on the tuinprising a pair of vertical rectangular mein- `l bersspaced apart and one of the same being operatively connected with the of the` tractor.'

ower plant linked tracksectlons passing over the tumblers and adapted to contact V5 with the ground at a level lower than theft.,V

'120 tion having a length equal to that .of one' guide members pro' lowest point of the tumblers, each track sec-t' side of the tumbler-s, Y jecting from the inner faces .of the track sectionsl and ada ted lto, pass betweenr the:

rectangular mem e x y guide tlietrack sections thereon, .and hinges members thereof.

4. A tractor including a frame, polygonal sided tumblers turnably mounted at each ersr'off the tumblers tobn -each""track section between the guide end of the frame, one of the tumblers being operatively connected with the power plant of the tractor, an endless track passing around the tumblers, each link of the track having a length equal to that of each side of the tumblers, and means whereby the track sections adjacent the ground are adapted to contact therewith at a level lowerthan that of the lowest point of the tumblers, such means including a frame pivotally mounted under the tractor frame for oscillatory movement relative thereto, and rollers turnably mounted at eacli end of the last named frame and adapted to rest on the inner faces of the track sections-when the latter are adjacent the ground.

5. A tractor including a frame, polygonal sided tumblers turnably mounted at each end of the frame, one of the tumblers being op eratively connected with the power plant of the tractor, an endless trackpassing around the tumblers, each link of the track having a Mlength equalgto that of each side of the tumblers, and Ieans whereby the track sections adjacent the ground are adapted to contact therewith at a level lower than that of the lowest point of the tumblers, such means including a frame pivotally mounted under the tractor frame for'oscillatory movement relative thereto, and `rollers turnably mounted at each end of the last named frame and adapted to rest on the inner faces of the track sections when the latter are adjacent the ground, the center of oscillation of the roller-frame being on a transverse line with that of a supporting wheel on the side of the tractor opposite from the endless track whereby when the plane of contact vof the tiller wheel is altered, the tractor will tilt about the oscillatory point as a pivot.

CHARLES A. MURDOCK.

Witnesses VERADINE WARNER, BERNARD PRIVAT. 

